The present invention relates to a machine for conditioning cigars, of which the characterizing features are as recited in the preamble of claim 1 appended.
The invention finds application in the art field of making and packaging cigars.
Before smoking a cigar, it is normal to pierce one end longitudinally so that the smoke can be drawn easily into the mouth when the cigar is lit.
To accomplish this operation, use has always been made of manual punch devices typically comprising a tubular body in which to locate the end of a single cigar, and a punch positioned to pierce the cigar when offered to the tubular body.
With the advent of mechanization and its impact on the manufacture of tobacco products generally, this piercing operation is now included among the functions of normal cigar making machines.
In effect, the prior art embraces piercing units that consist in heads equipped with a plurality of needles positioned so as to engage a corresponding plurality of cigars disposed parallel one with another and arranged in an ordered succession.
More exactly, ordered groups of cigars advancing through the machine are directed into a piercing station and thereupon held stationary so that they can be engaged by the aforementioned heads carrying the needles.
The needles are heated so that the tobacco can be subjected to what is in effect a stretching action, designed to ensure that the hole retains its shape rather than closing up once the needle has been withdrawn.
For this heat-stretching action to be effective, clearly enough, the needle must remain in the hole for a certain period of time.
Consequently, the feed unit by which the cigars are advanced must pause for a duration at least equal to the period of time in question.
Conventional machines thus betray the drawback of requiring lengthy cycle times, and this has obvious repercussions on the operating efficiency and the profitability of such machines.
Another drawback connected with the use of prior art machines is that, in seeking to avoid further prolongation of the pause, attempts have been made to speed up the steps of inserting and withdrawing the needle into and from the cigar; this expedient has negative consequences however, since the cigars can suffer damage from the substantially impulsive action of the needle.
Furthermore, the needles will be heated typically by thermal conduction, utilizing a heating element carrying electric current, which is positioned to engage each needle directly and supplied with power by way of sliding contacts.
Because the heating step occurs with the passage of heat between an electrically warmed body and the needle, monitoring the temperature of the needle is somewhat problematical. In particular, considerable difficulty is experienced in seeking to regulate the temperature of the needle according to the time it dwells in the cigar, to the operating speed of the machine, also to the ambient temperature, with the end in view of obtaining a product such as will respond accurately and repeatably to a required set of characteristics.
The object of the present invention is to provide a machine for conditioning cigars such as will be affected neither generally nor even in part by the drawbacks mentioned above, remaining nonetheless functional and economical to operate.